The present invention relates to pigment mixtures in dispersion or in the form of a powder, consisting of at least two components, where component A comprises BiOCl pigments in the form of a powder or dispersion, and component B comprises pearlescent pigments, platelet-shaped, needle-shaped or spherical colorants and/or fillers, and to the use thereof in paints, coatings, printing inks, plastics, powder coatings, plastic films, for the finishing of seed and in particular in cosmetic formulations.
Since BiOCl pigments have a high refractive index (n=2.15) and a pearl-like or metallic silver lustre, they are employed in paints, coatings, plastics and in particular in cosmetic products. In addition to the metallic silver lustre or pearl lustre, the consumer of decorative products expects ever greater functionality and thus makes ever greater demands on the appearance. The BiOCl pigments disclosed in German Patent 10 03 377, U.S. Pat. No. 2,975,053, DE 24 11 966, EP 0 496 686 B1 and DE 43 05 280 A1 have the disadvantage that they either do not have variable hiding power, have inadequate metallic lustre, do not have an absorption colour, do not have an interference colour and/or do not have a light diffusing effect.
The object of the present invention was to provide a pigment mixture comprising BiOCl pigments which is distinguished by high, variable hiding power or variable transparency and/or increased metallic lustre, can be incorporated well into the respective application system and is stable therein, and in which a visible BiOCl/colorant or BiOCl/filler separation in the system is substantially excluded. Furthermore, the abrasion, application and skin feel in cosmetic materials should be improved compared with the products on the market.
Surprisingly, a pigment mixture has now been found which has none of the above-mentioned disadvantages. The pigment mixture according to the invention consists of at least two components, where component A comprises coated or uncoated BiOCl pigments in the form of a powder or dispersion, and component B comprises pearlescent pigments, in particular based on mica, SiO2, glass, Al2O3, TiO2, graphite or polymer platelets, platelet-shaped, needle-shaped or spherical colorants and/or fillers.
The admixing of component B with the BiOCl pigments enables increased metallic lustre to be imparted to the application systems, the colour effect is increased, and novel colour effects are achieved. At the same time, the pigment mixture is distinguished by its variable, i.e. controllable, hiding power from virtually invisible to strongly hiding. In addition, the functionality of the end product is improved. Formulations comprising the pigment mixture according to the invention have an excellent skin feel, high skin affinity, long-wear properties, variable hiding power, if desired metallic lustre, good ease of incorporation into the end product, and comparatively high light stability.
The invention thus relates to a pigment mixture consisting of at least two components, where component A comprises coated or uncoated BiOCl pigments in the form of a powder or dispersion, and component B comprises pearlescent pigments, platelet-shaped, needle-shaped or spherical colorants and/or fillers.
The invention likewise relates to the use of the pigment mixture according to the invention in paints, coatings, printing inks, including printing inks for security printing, plastics, plastic films, powder coatings, for the finishing of seed and in particular in cosmetic formulations.
The BiOCl pigments in the form of a powder can be mixed with component B in any ratio. The ratio of component A to component B is preferably from 1:90 to 90:1, particularly preferably from 1:50 to 50:1 and in particular from 1:20 to 20:1.
BiOCl pigments are commercially available and are offered, for example, by Merck KGaA, Germany, under the trade names Biron(copyright), Bital(copyright), Bicrona(copyright), Mibiron(copyright) and Nailsyn(copyright). Owing to the diverse production possibilities, BiOCl pigments having different optical properties, from matt to glossy and from transparent to hiding, are obtainable. The size of the individual particles is 1-100 xcexcm, preferably 1-40 xcexcm and in particular 2-35 xcexcm. The BiOCl pigments employed may be coated or uncoated. In the case of the coated BiOCl pigments, the coating preferably consists of metal oxides, such as, for example, TiO2, TiO2 sub-oxides, Fe2O3 and mixtures thereof or organic or inorganic colorants of natural and synthetic origin. Preferred pigment mixtures comprise BiOCl pigments which are coated with Fe2O3, Carmine Red, Berlin Blue or Chromium Oxide Green.
As a dispersion, the BiOCl is preferably initially in the form of a paste with nitrocellulose lacquers or castor oil and is subsequently mixed with component B. The pigment mixture according to the invention in the form of a powder or dispersion is distinguished by good dispersibility, pH stability, heat stability and storage stability in the end product.
Besides pastes with castor oil and nitrocellulose lacquers, dispersions in water, polar and nonpolar oils, polyols, hydrophilic and hydrophobic solvents, volatile or non-volatile, are likewise suitable.
Preferred pigment mixtures comprise, in particular, one or more pearlescent pigments as colorant (=component B) in addition to the BiOCl pigments (=component A). The pearlescent pigments used are, in particular, pigments based on platelet-shaped, transparent or semi-transparent substrates made from, for example, phyllosilicates, such as, for example, synthetic or natural mica, talc, sericite, kaolin, or other silicate materials, which are coated with coloured or colourless metal oxides, such as, for example, TiO2, titanium sub-oxides, titanium oxynitrides, pseudobrookite, Fe2O3, Fe3O4, FeOOH, SnO2, Cr2O3, ZnO, CuO, NiO and other metal oxides, alone or in the form of a mixture in a single layer or in successive layers.
Pearlescent pigments are disclosed, for example, in the German patents and patent applications 14 67 468, 19 59 998, 20 09 566, 22 14 454, 22 15 191, 22 44 298, 23 13 331, 25 22 572, 31 37 808, 31 37 809, 31 51 343, 31 51 354, 31 51 355, 32 11 602, 32 35 017, 38 42 330 and 44 45 394 and are commercially available, for example under the trade names Colorona(copyright), Timiron(copyright), Dichrona(copyright), Microna(copyright) and Soloron(copyright), from Merck KGaA, Darmstadt, Germany.
Particularly preferred pigment preparations comprise TiO2, Fe2O3, TiO2 sub-oxides, TiO2/Fe2O3, Fe3O4, FeOOH or FeOOH/TiO2 mica pigments. Preference is furthermore given to TiO2, graphite, Fe2O3, SiO2 or Al2O3 platelets coated with TiO2 and/or Fe2O3.
Further suitable platelet-shaped pigments are, in particular, pearlescent pigments based on SiO2 platelets, Al2O3, graphite, polymer or TiO2 platelets or glass platelets which are covered with one or more metal-oxide layers (one, two, three, five or seven).
Also suitable as component B are the multilayered pigments disclosed, for example, in DE-A 196 18 563, DE-A 196 18 566, DE-A 196 18 569, DE-A 197 07 805, DE-A 197 07 806 and DE-A 197 46 067. These are based on a platelet-shaped, transparent, coloured or colourless matrix consisting of mica (synthetic or natural), SiO2 platelets, glass platelets, Al2O3 platelets, TiO2 platelets or polymer platelets and generally have a thickness of between 0.3 and 5 xcexcm, in particular between 0.4 and 2.0 xcexcm. The extension in the two other dimensions is usually between 1 and 250 xcexcm, preferably between 2 and 100 xcexcm, and in particular between 5 and 40 xcexcm. The multilayered pigments consist of the matrix (substrate) coated with metal oxides (at least two). The coating of the substrate platelets, such as, for example, mica, SiO2 platelets, glass platelets or Al2O3 platelets, with a plurality of layers is carried out in such a way that a layer structure consisting of alternating high- and low-refractive-index layers is formed. The multilayered pigments preferably comprise 2, 3, 4, 5, 6 or 7 layers, in particular 3, 4 or 5 layers. Suitable high-refractive-index metal oxides are, for example, titanium dioxide, zirconium oxide, zinc oxide, iron oxides, iron-titanium oxides (iron titanates) and/or chromium oxide, in particular TiO2 and/or Fe2O3. The low-refractive-index metal oxides used are SiO2 and Al2O3. However, MgF2 or an organic polymer (for example acrylate) can also be employed for this purpose. The substrate platelets can be coated, for example, as described in WO 93/08237 (wet-chemical coating) or DE-A 196 14 637 (CVD process).
Preferred multilayered pigments have the following structure:
substrate+Fe2O3 layer+SiO2 layer+Fe2O3 layer
substrate+Fe2O3 layer+SiO2 layer+TiO2 layer
substrate+TiO2 layer+SiO2 layer+Fe2O3 layer
substrate+TiO2 layer+SiO2 layer+TiO2/Fe2O3 layer
substrate+TiO2/Fe2O3 layer+SiO2 layer+TiO2/Fe2O3 layer
substrate+TiO2 layer+SiO2 layer+Cr2O3 layer
substrate+TiO2 layer+SiO2 layer+TiO2 layer
Instead of the outer metal-oxide layer, it is also possible to use a semi-transparent layer of a metal. Suitable metals for this purpose are, for example, Cr, Ti, Mo, W, Al, Cu, Ag, Au or Ni.
In order to achieve specific colour effects, finely divided particles in the nanometre size range may additionally be incorporated into the high- or low-refractive-index layers. Suitable for this purpose have proven to be, for example, finely divided TiO2 or finely divided carbon (carbon black) having particle sizes in the range 10-250 nm. The light-scattering properties of particles of this type enable the lustre and hiding power to be modified in a targeted manner.
The pearlescent or multilayered pigments in component B may also be provided with a protective layer in order to improve the light, weathering and chemical stability or in order to increase the compatibility in various media. Suitable subsequent coatings or subsequent treatments are the processes described, for example, in DE 22 15 191, DE 31 51 354, DE 32 35 017 or DE 33 34 598. The additionally applied substances make up only from about 0.1 to 5% by weight, preferably from 0.5 to 3.0% by weight, of the multilayered pigment.
Suitable as component B for the pigment mixture according to the invention are all platelet-shaped, needle-shaped and spherical colorants or fillers known to the person skilled in the art which have a particle size of from 0.001 to 20 xcexcm, preferably from 0.01 to 5 xcexcm. The pigment mixtures according to the invention preferably comprise absorption pigments as colorants and platelet-shaped or spherical powders as fillers.
Particularly suitable are platelet-shaped substrates which, on the basis of mica, are coated with an organic and/or inorganic dye of synthetic or natural origin.
The spherical colorants include, in particular, TiO2, BaSO4, coloured or coated SiO2, CaSO4, iron oxides, chromium oxides, carbon black, organic and inorganic coloured pigments of synthetic or natural origin, such as, for example, carmine, Berlin Blue, anthraquinone pigments, quinacridone pigments, diketopyrrolopyrrole pigments, phthalocyanine pigments, azo pigments and isoindoline pigments. Of the spherical colorants, SiO2 is preferred. The SiO2 beads may be coated or uncoated. The SiO2 beads are preferably coated with TiO2, Fe2O3, FeOOH, Fe3O4, Berlin Blue or chromium oxide green in one or more layers. The spherical particles, for example made of SiO2, preferably have a TiO2/Fe2O3, SiO2, TiO2/Fe2O3 coating or a TiO2, SiO2, TiO2 coating.
Of the multicoated SiO2 beads, particular preference is given to those which are coated alternately with 3, 5 or 7 layers of metal oxides of different refractive indices. Spherical SiO2 particles having a particle size of from 1 to 30 xcexcm are commercially available, for example under the trade names Ronasphere(copyright) and Micronasphere(copyright) from Merck KGaA.
The needle-shaped pigments are preferably ZnO, Fe2O3, coloured glass fibres, xcex1-FeOOH, organic coloured pigments, such as, for example, azo pigments, xcex2-phthalocyanine Cl Blue 15:3, Cromophtal Yellow 8GN (Ciba-Geigy), Irgalith Blue PD56 (Ciba-Geigy), azomethine copper complex Cl Yellow 129 or Irgazine Yellow 5GT (Ciba-Geigy). Particular preference is given to needle-shaped Fe2O3.
The addition of a UV stabiliser to the pigment mixture according to the invention is frequently advisable, in amounts of from 0.01-10% by weight, preferably 0.01-5% by weight and in particular 0.01-3% by weight, based on the BiOCl content. Particularly suitable UV stabilisers are those which are commercially available under the name Eusolex(copyright) (Merck KGaA), such as, for example, Eusolex(copyright) 4360, a 2-hydroxy4-methoxybenzophenone. Also suitable are organic and inorganic light-protection filters in the form of a powder or in dispersion, for example based on micronised TiO2, such as, for example, Eusolex(copyright) T-2000 or Eusolex(copyright) T-Aqua.
The pigment mixture according to the invention is simple and easy to handle. The pigment mixture can be incorporated into the application system by simple stirring-in in the form of a powder or in the form of a dispersion. Complex grinding and dispersion of the pigments is unnecessary.
The pigment mixture according to the invention can be used for the pigmentation of paints, powder coatings, coatings, printing inks, security printing inks, plastics, artificial pearls and jewellery articles, agricultural sheeting, seed coatings, button pastes and in cosmetic formulations, such as, for example, lipsticks, nail varnishes, cosmetic sticks, powder compacts, make-ups, shampoos, loose powders and gels.
The pigment mixture according to the invention is furthermore suitable for rendering an X-ray catheter tube in which it is incorporated readily visible to the doctor on the X-ray screen. Due to the pigment mixture, the tube remains flexible and smooth.
The concentration of the pigment mixture in the application system to be pigmented is generally between 0.1 and 70% by weight, preferably between 0.1 and 50% by weight and in particular between 1.0 and 20% by weight, based on the total solids content of the system. It is generally dependent on the specific application.
Plastics comprising the pigment mixture according to the invention in amounts of from 0.01 to 50% by weight, preferably from 0.01 to 25% by weight, in particular from 0.1 to 7% by weight, based on the plastic composition, are frequently distinguished by particular metallic lustre.
In the coatings area, the pigment mixture is employed in amounts of from 0.1 to 30% by weight, preferably from 1 to 10% by weight, based on the coating dispersion. The mixing ratio of the BiOCl pigments with component B depends on the desired effect. The BiOCl pigments are preferably employed with component B in a ratio of from 10:1 to 1:10. Compared with finishes comprising only a pearlescent pigment based on mica, finishes comprising the pigment mixture according to the invention have significantly higher metallic lustre.
The pigment mixture according to the invention can also advantageously be employed in decorative and care cosmetics. The high-lustre BiOCl dispersions in combination with component B are preferably employed in pastes, in particular in lipsticks and nail varnishes. Mixtures according to the invention comprising flake-like, irregular BiOCl pigments in the form of a powder are used, in particular, in eye shadow, rouge, cosmetic sticks and make-up powders of all types. In decorative cosmetics, the pigment mixtures according to the invention enable particularly uniform application of the powder to the skin and result in an improvement in the skin feel and in a light diffusing wrinkle hiding effect. In addition, the skin adhesion is improved and cracking during pressing is prevented. Furthermore, the pigment mixture according to the invention in the cosmetic formulation exhibits an improvement in abrasion or application and in distribution, variable hiding power from transparent to hiding and/or a lustre from matt to glossy.
The use concentration and the mixing ratio of BiOCl pigments with component B, in particular organic and inorganic coloured pigments and dyes, of natural or synthetic origin, such as, for example, chromium oxide, ultramarine, coated or uncoated spherical SiO2 or TiO2 pigments, as disclosed, for example, in DE-A 198 42 134, are dependent on the application medium and the effect to be achieved. The mixing of BiOCl pigments in the form of a powder or dispersion with other pigments or dyes can take place in all ratios, the ratio preferably being from 1:10 to 10:1. The use concentration extends from 1% by weight in nail varnish to 70% by weight in powder compacts. In a mixture of BiOCl pigments with spherical fillers, for example SiO2, the concentration can be 0.01-70% by weight in the formulation. The cosmetic products, such as, for example, nail varnishes, lipsticks, powder compacts, shampoos, loose powders and gels, are distinguished by particularly interesting gloss and/or colour effects. In lipsticks and nail varnishes, the pigment mixture is used, in particular, in the form of a dispersion. For use in lipsticks, 70% pigment mixture pastes are preferably used.
Nail varnishes preferably comprise thixotropic, toluene-free, formaldehyde-free nitrocellulose pastes of the pigment mixture. The nitrocellulose pastes generally comprise 40-75% by weight of nitrocellulose and 25-60% by weight of pigment mixture. The metallic silver lustre in nail varnish can be significantly increased with the aid of the pigment mixtures according to the invention compared with conventional nail varnishes. Furthermore, the pigment mixture according to the invention can be employed in bath additives and toothpastes.
In the pigmentation of binder systems, for example for paints and printing inks for gravure printing, offset printing or screen printing, or as precursor for printing inks, for example in the form of highly pigmented pastes, granules, pellets, etc., pigment mixtures consisting of BiOCl pigments with spherical colorants, such as, for example, TiO2, carbon black, chromium oxide, iron oxide and organic xe2x80x9ccoloured pigmentsxe2x80x9d have proven particularly suitable. The pigment mixture is generally incorporated into the printing ink in amounts of 2-35% by weight, preferably 5-25% by weight and in particular 8-20% by weight. Offset printing inks may comprise the pigment mixture in an amount of up to 40% by weight or more. The precursors for printing inks, for example in the form of granules, pellets, briquettes, etc., comprise up to 95% by weight of the pigment mixture according to the invention in addition to the binder and additives. The mixing ratio of component A to component B is preferably in the range from 1:10 to 10:1. Printing inks comprising the pigment mixture according to the invention exhibit purer hues and can be printed better owing to the good viscosity values.
The invention thus also relates to formulations comprising the pigment mixture according to the invention.
The following examples are intended to illustrate the invention, but without restricting it.